Oscillating power unit

ABSTRACT

An oscillating power unit for use with a variety of tools and equipment that are vibrated in their operation. An inertial mass rocking about a fixed pivot is driven by an orbital motion eccentric mechanism in such a manner that the effective power is concentrated along one axis of motion and minimized in all other directions. The eccentric drive has a variable throw that is easily adjusted to selectively vary the oscillating power output when the unit is installed in an operating assembly without dismantling the structure, although all moving parts except the drive shaft are fully enclosed.

United States Patent [72] Inventor Olly 0. Stoflel San Diego, Calif.

[21 1 Appl. No. 859,089

[22] Filed Sept. 18, 1969 [45] Patented Aug. 24, 1971 [7 3] AssigneeStoflel Engineering Corporation San Diego, Calif.

[54] OSCILLATING POWER UNIT 87, 55, 571, 571 M; 173/49; 175/55; 259/1;209/325, 326, 327, 365 R, 365 A, 335; 198/220 [56] References CitedUNITED STATES PATENTS 2,776,573 1/1957 Willi 74/55 2,335,645 11/1943Celio 74/571 R 2,947,183 8/1960 Carrier, Jr. et al 74/61 2,592,2374/1952 Bradley 74/571 R 3,189,106 6/1965 Bodine, Jr. 74/61 PrimaryExaminer-Martin P. Schwadron Assistant Examiner-Barry GrossmanAttorney-Carl R. Brown ABSTRACT: An oscillating power unit for use witha variety of tools and equipment that are vibrated in their operation.An inertial mass rocking about a fixed pivot is driven by an orbitalmotion eccentric mechanism in such a manner that the effective power isconcentrated along one axis of motion and minimized in all otherdirections. The eccentric drive has a variable throw that is easilyadjusted to selectively vary the oscillating power output when the unitis installed in an operating assembly without dismantling the structure,although all moving parts except the drive shaft are fully enclosed.

PATENTEUAUBZMQH 3.600857 sum 1 OF 5 INVIiNTUR. OLLY O. STOFFEL ATTORNEYPATENTEU AUB24|97| 3600.957

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sum u UF 5 INVENT OLLY O. STOFF ATTORNEY ATENTEU M1824 l9?! SHEET 5 UP 5cmzg ATTORNEY OSCILLATING POWER UNIT BACKGROUND OF THE INVENTIONVibrators, oscillating power devices and other such devices, used on avariety of tools and machines, such as rock crushers, digging and boringapparatus, rippers, and the like, generally incorporate some type ofinertial mass that is rotated or swung about an axis to generate areciprocating power force. These mechanisms are normally designed sothat the greatest effective power occurs in given directions, butunwanted forces also occur in other directions and the mechanisms musteither be limited in maximum power output or be designed with excessstrength to withstand the loads. Even where the mechanisms are designedto withstand the loads, the devices to which they are attached oftencannot withstand the excessive forces. Some vibrators have used dualinertial masses that are synchronized to work together in one directionand oppose each other in other directions. These are cumbersome for thepower developed and they do not entirely solve the problem. Furthermore,the power output of such vibrators is usually difficult or impossible toadjust without dismantling the apparatus, and the speed or pulse rate isoften the only reasonably, adjustable variable.

Thus it is advantageous to have an oscillating power unit that iscapable of providing large oscillating or reciprocating power outputfrom a compact unit, which power output is easily controlled.

SUMMARY OF THE INVENTION In an illustrative embodiment of thisinvention, the oscillating power unit has an inertial mass oscillatormounted for a rocking action in the plane of useful power output, and isdriven by an orbital eccentric mechanism in such a manner that maximumpower is produced along one axis and force moments in other directionsare minimized. All moving parts except an extending drive shaft arefully enclosed in a compact casing and the unit is readily adaptable tovarious tools and machines requiring a controlled vibratory action. Inaddition to speed control, the power output is also adjustable byvarying the eccentric stroke. This is easily accomplished throughconveniently located access in the casing, without dismantling the unitor disturbing its mounting.

The orbital eccentric mechanism has means for translating rotation of adrive shaft to reciprocating, linear pivotal movement of the eccentricmechanism within the inertial mass, that moves the oscillator mass in areciprocating, rocking, movement about a fixed offset pivot. Theinternal forces between the eccentric mechanism and the oscillator massin translating force from the shaft to the oscillator mass, createsreciprocating force moments along a given axis, and absorbs forcemoments in other directions. The amount of force generated isselectively set by rotatably positioning one eccentric member withinanother eccentric member within the eccentric mechanism. This allowsselective setting of the throw of the eccentric mechanism and therocking movement of the oscillator and thus selective setting of theoscillating force generated.

It is therefore an object of this invention to provide a new andimproved oscillating power unit.

Other objects and many advantages of this invention will become moreapparent in reading the following detailed description wherein likereference numerals designate like parts throughout and in which:

FIG. I is a side elevation of an embodiment of the invention.

FIG. 2 is an illustration of a typical use of an embodiment of theinvention.

FIG. 3 is an enlarged sectional view taken on line 33 of FIG. 1.

FIG. 4 is a sectional view taken on line 44 of FIG. 3.

FIG. Sis a sectional view taken on line 5-5 of FIG. 4.

FIG. 6a to 60 show three different adjustments of eccentric throw indiagrammatic form.

FIGS. 7a to 7f are diagrams of six positions of the mechanism throughone complete cycle of operation.

The power unit is contained in a cylindrical casing 10 enclosed by endplates 12 and mounted on a base frame 14 for convenience of attachmentto various apparatus by any known suitable means. As illustrated, theframe 14 comprises a base plate 16 and a pair of arcuate saddle members18 in which casing 10 is seated, but the configuration may varyaccording to specific use.

Inside casing 10 is a substantially discoid inertial weight element oroscillator 20, that is pivoted near its lower edge on a rocker pin orshaft 22 extending across the casing 10 parallel to the axis of thecylindrical casing. The oscillator 20 is smaller than the interior ofcasing 10 to allow clearance for a rocking motion and is slightlyelongated in a direction radial to pin 22. This minimizes clearance atthe top and bottom while allowing sufficient clearance at the sides. Inthe center of oscillator 20 is a large void opening 24 that is elongatedhorizontally and extends axially through the complete thickness of theoscillator 20. Fixed in the opposite ends of opening 24 are verticalwear plates 26 with parallel opposed faces. The opposite ends of rockerpin 22 are held in sockets 28 of cap members 30 which are inset inopenings in the end plates 12 as illustrated in FIG. 3. The cap members30 are secured to the end plates 12 by bolts 94 and cap screws 32 closethreaded openings through which studs are inserted to facilitate removalof the cap members 30.

Mounted in the opening 24 is a generally avoid slide block 36, with sideplates 38 fixed to opposite ends to slide smoothly on wear plats 26. Inthe center of slide block 36 is a large circular bore 40 containingaxially positioned roller bearings 42 with bearing races 43. Mounted inthe bearings 42 is an eccentric drive block 44. The drive block 44 issplit longitudinally on a vertical plane into two portions designated44a and 44b, which are connected by axially extending, circumferentiallyspaced bolts 46. The heads 47 of bolts 46 abut against the opening inportion 44a and the threaded ends 49 engage the portion 44b. The heads47 have known socket springs 48 retained in opposed sockets 50 betweenthe two drive block portions, as illustrated in FIG. 3. To retain slideblock 36 in centered alignment, guide plates 52 are inset in oscillator20 along opposite ends of wear plates 26, and project inwardly over theends of slide plates 38.

Drive block 44 is driven by a drive shaft 54 extending axially throughcasing 10, the ends being journaled in suitable bearings 56. Thebearings 56 are held in bearing plates which, for purposes ofdescription, are designated front bearing plate 58 and back bearingplate 60, inset in and secured to end plates 12 by bolts 95. In thefront bearing plate 58 are set screws 62 that engage and apply axialload to the bearing therein, to eliminate axial play. Drive shaft 54 hasan eccentrically enlarged central lobe 64 with tappered cylindricalshoulders 66 and reduced end portions 68. Drive blocks 44a and 44b haveeccentrically offset bores 70 shaped to fit closely on the lobe 64 andshoulders 66, so that clamp bolts 46 can be tightened to lock the driveblock portions on the tapered shoulders with a jamming action for apositive drive connectron.

As may be seen in FIGS. 3 and 4, the aligned openings 71 in the driveblocks 44a and 44b are offset from the axis of the drive shaft 54. Thusthe upper radial thickness of the drive blocks is greater than the lowerradial thickness. Also the center of the enlarged central lobe 64 isoffset from the axis of the shaft 54. Since the shaft 54 is rotatablewithin openings 71, the offset openings 71 and the central lobe 64 forman eccentric positioning of the two masses, which eccentric positioningis adjustable. Such adjustment allows the total mass of the two members,the lobe 64 and the drive blocks 44, and their radial displacementrelative to the drive shaft axis to be selectively set, thus providingfor selectively setting the throw or strape of the eccentric mechanism.The drive assembly thus comprises an eccentric within an eccentric andis easily adjusted to vary the stroke.

In the front bearing plate 58, are removable access plugs 72 that arespaced to coincide axially with the locations of clamp bolts 46 at aparticular position of the eccentric assembly, as illustrated in FIG. 5.To locate this position, an indexing pin 74 is mounted on front bearingplate 58 and is biased by a spring 76 to seat into a radial slot 78 indrive block 44a. Indexing pin 74 has an enlarged head 80 with webportions 82 which normally rest in shallow grooves 84 in a boss 86projecting from the bearing plate coaxial with the pin. In this positionthe indexing pin is held clear of slot 78, as in FIG. 3. To look theeccentric, the pin is turned 90 so that the web portions 82 can dropinto deep grooves 88 in boss 86, allowing the pin 74 to enter the slot.With the eccentric so locked and access plugs 72 removed, the clampbolts 46 are loosened and separator springs 48 push the drive blockportions apart. Since pin 74 is secured to end plate 12, the locked pinalso holds the drive blocks 44 in the illustrated position. Thus driveshaft 54 can be rotated relative to the drive blocks 44, changing theeccentric relation of lobe 64 to the eccentricity of bores 70. The driveshaft 54 has a slot 57 in the end thereof, which slot may be used tocalibrate the position of the two eccentrics and thus the throw orstroke of the oscillator. However other suitable and more precisecalibration markings may be used. The slot 78 has a vertical extensionto allow for slight vertical movement of the drive blocks 44 that occursas a result of relative rotational movement between the two eccentrics.At the desired eccentric setting, the clamp bolts are tightened to lockthe assembly and the access plugs 72 are replaced and indexing pin 74 iswithdrawn and locked out.

To illustrate the changes in throw available, FIGS. 6a, 6b and 6c showthree different eccentric positions. A reference marker 90 is used ondrive block 44 and a reference marker 92 on lobe 64 to clarify thepositions. In FIG. 6a the assembly is set for maximum throw T, with bothreference markers radially aligned. In this position, the axial centerof shaft 54 is at point 91, the axial center of the assembly is at 93and the axial center of lobe 64 is at 61. Thus the radial throw of thedouble eccentric mechanism is the throw T. This represents the distancethat the oscillator 20 will be rocked in each direction and alsodetermines the relative up and down and sideward movement of the driveblocks 44, and thus the slide block 36. This maximum throw position isalso illustrated in FIGS. 3 and 4. In FIG. 6b, shaft 54 is rotated 90and the eccentrics are at an intermediate position, with thedisplacement between center points 91 and 93 giving a reduced throw ofT1. FIG. 6c illustrates the markers 90 and 92 substantially opposed withthe throw T2 reduced to zero. It may be understood that in thisposition, the eccentric of the lobe 64 exactly equals the eccentric ofthe drive blocks 44. Thus the two eccentrics exactly equal each otherand the center of the mass and throw 93 is on the axis of the driveshaft 54. Thus rotation of the drive shaft 54 rotates the drive block 44without imparting rocking motion to the oscillator 20.

The various components are shown as being secured by suitably sizedbolts or cap screws 94 with the end plates 12 held in accurate alignmentduring assembly by dowel pins 96. Specific configurations and assemblydetails will depend on materials used and the size of the unit.

To provide lubrication of the assembly, the oscillator 20 has oilpassages 101 and side oil passages 105, the slide block 36 has oilpassages 103 and the bearing races 43 have oil passages 107. Inoperation, the oil in the unit is normally carried at a levelillustrated by dotted lines 111. The oscillator 20, in its rockingmovement, drives oil upward through openings 105 and 101 and around theouter surface 113 to the upper space between the oscillator 20 and theslide block 36. The oil then passes through the upper oil holes 101 tothe slide block 36 and also flows down the outer surface of theoscillator 20. The slide block 36 in the up and down movement contactsthe oil and moves it upwardly through lower holes 103 as well as passingoil through upper holes 103 to the bearings 42 through holes 105. Oilalso moves through upper holes 101 and over the outer surface of theslide block 36 to the bearings surfaces between plates 26, 38 and 52.Pin 22 having oil grooves 34 receives oil through holes 101. The oil maybe inserted into the system through the upper valve 109 and hole 107.Valve 109 may be an appropriate pressure set check valve to releasepressure buildup or equalize pressure in the internal volume of theoscillating power unit. The oil level 1 11 is sufficient to provide oilto the rotating drive blocks.44 when the eccentric members are set forzero throw.

The spacing between the surface 115 of the oscillator 20 and the innersurfaces of the end plates. 12 is sufficient to pass oil to the bearings56. Also the surfaces 115 of the oscillator 20 have oil grooves (notshown) to provide controlled oil flow between the adjacent surfaces ofthe oscillator 20 and the end plates 12. Known seals 49, prevent oilleaks around the drive shaft 54.

OPERATION In operation, a suitable power source is connected to thedrive shaft 54. The eccentric mechanism is then set for the desiredamount of throw in the manner previously described. The drive shaft 54is then rotated, rotating the drive blocks 44 in bearings 42. Sincethere is an offset of the combination drive lobe 64 and the drive blocks44, the slide block 36 is moved sideways and up and down. This movementcauses the slide block 36 to slide vertically relative to the oscillator20 and to move the oscillator in a reciprocating, rocking movementaround pin 22. This movement is illustrated in FIGS. 7a to 7f, with thedrive blocks 44 movement illustrated in 60 increments of clockwiserotation. For reference purposes, the rotation center of axis of driveshaft 54 is indicated by circle 98, with the particular location of thethrow of the lobe 64 and drive blocks 44 being indicated by numeral 65.

In FIG. 7a, the eccentric mechanism has the throw in the upward verticalposition and the slide block 36 at the top of its stroke. As the driveshaft 54 rotate clockwise, the slide block 36 is moved to the right anddownwardly. This pivots the oscillator 20 to the right. As the driveshaft 54 continues to rotate, the slide bearing block and the oscillator20 moves to the right to the maximum extent for the given eccentricsetting. As the slide block 36 moves downward, it also moves back towardthe center position pulling the oscillator 20 from the maximum throw tothe right. The drive shaft 54 in its rotational movement moves the slideblock 36 to the downward position illustrated in FIG. 7d and thencontinues in movement to the left in the same manner as previouslydescribed in the movement to the right. Thus the slide block movesvertically with side movements generally defining a circular movementcorresponding to the circular movement of the lobe 64 and drive blocks44.

The oscillator power unit provides force moments only in substantiallythe horizontal direction, which is in the direction of arrows 151 and153. Thus while the slide block 36 has a vertical component of motion,there is almost no vertical oscillation force produced in the unit. Inthe lateral motion of the mechanism, the inertia of the slide block 36is added to the inertia of the oscillator 20, the latter being effectiveabout the axis of rocker pin 22 and thus has a long lever arm. The massof the slide block 36, including the drive blocks 44 and lobe 64, isonly a part of the moving assembly and is effective over a smaller leverarm than the whole mass. In addition the energy of the slide block 36 isapplied to the weight element through the sliding members 26 and 38,which are inclined to vertical throughout most of the cycle ofoscillation. Due to the shallow angle of inclination, as will beapparent in FIGS. 7b, 7c, 72 and 7f the energy of the driven slide block36 is absorbed in imparting a lateral motion to the oscillator 20. Whenthe slide block mass passes downward through the midpoint of themechanism, the slide block is exerting force against the oscillator 20to reverse the rocking movement of the oscillator 20. Thus the verticalforce component of the sliding block is absorbed in moving theoscillator 20 and the horizontal throw of the mass provides thehorizontal force components.

In apparatus for which the unit is applicable, the component to bevibrated is usually mounted for motion in a particular plane or along asingle axis. If the vibrating mechanism has an effect in a directionother than that desired, the structure must be strengthen to withstandthe stress which is not always practical. With the present unit suchreinforcement is unnecessary. A typical use of the unit is illustratedin simple form in FIG. 2. The complete oscillating power unit 100 ismounted on top of a ripper device having a shank 102 carrying a workingtooth 104, or similar ripping structure. The shank 102 is pivotallyattached to a frame support 106 to swing from front to rear, asindicated by the directional arrows. The frame has tow bar means 108 forattachment to a vehicle, the power unit being operated as the assemblyis towed with the working shank 102 below ground so that the vibrationeases penetration. Any

. suitable motor or power source, not shown, may be used to drive theunit. This is merely one example of use of the oscillating power unitwhich has many other uses and is not necessarily limited to an uprightposition as illustrated.

The adjustable throw of the eccentric mechanism makes it possible tocontrol the power output without changing speed, which is an advantagewith apparatus having frequency or resonance limitations. Suchadjustment can be made as described above without dismantling orremoving the unit from the associated apparatus. The rocking action ofthe oscillator 20 and sliding of the slide block 36 provide effectivepumping action to circulate lubricant with the unit. The oil level maybe selectively changed to conform, as desired, to different amounts ofeccentric throw or vertical movement of the slide block. Because of thecompactness and low inertia of the eccentric mechanism itself, the unitis capable of very rapid starting and stopping and the inertia of theoscillator 20 acts as a brake by applying pressure to the slide blockwhen driving power is shut off causing the slide block and power shaftto stop substantially instantly.

Having described my invention, I now claim.

1. An oscillating power unit comprising:

a hollow casing having enclosing end plates thereon,

a drive shaft rotatably mounted in said casing between said end plates,

a rocker pin fixed in said casing substantially parallel to and radiallyoffset from said drive shaft,

an oscillatory power generating weight element pivotally mounted on saidrocker pin and enclosing said drive shaft,

and adjustable throw eccentric drive means coupling said drive shaft tosaid weight element.

2. The structure of claim 1 wherein:

said drive means include an eccentric lobe on said drive shaft,

and a drive block eccentrically mounted on said lobe within said weightelement.

3. The structure of claim 2 wherein:

said weight element has a slide block mounted therein for sliding motionsubstantially radial to said rocker pin, said drive block beingrotatably held in said slide block.

4. The structure of claim 3 wherein:

said drive block has clamp means adjustably securing it to said driveshaft.

5. The structure of claim 3 wherein:

said lobe has axially tapered portions, said drive block being in twoaxially separated elements seating on said tapered portions with clampmeans securing the separated elements together.

6. The structure of claim 5 wherein:

one of said end plates has removable elements exposing said clamp means.

7. The structure of claim 6 including:

indexing means on said casing, selectively engageable with said driveblock in one position in which said clamp means are aligned with saidremovable elements.

8. An oscillating power unit comprising: an oscillator pivotallysupported at one side for radial rockin movement around the pivot, saidoscllator having a rotatable eccentric means positioned within saidoscillator and enclosed thereby and spaced radially from said pivot forproviding an orbital movement with a rotating eccentric throw, and saideccentric means has a linear sliding drive connections with saidoscillator and within said oscillator for translating said orbitalmovement to reciprocating, radial rocking movement of said oscillator onsaid pivot. 9. An oscillating power unit as claimed in claim 8 in which:said eccentric means and said pivot each have an axis of rotation, whichare parallel and are in the same plane. 10 An oscillating power unit asclaimed in claim 9 in which: said oscillator has an opening withopposite linear sides, said sides are parallel with said plane, and anopen space between the upper and lower edges of said eccentric means andsaid oscillator opening allowing linear movement of said eccentric meansin said oscillator opening. 11. An oscillating power unit as claimed inclaim 10 in which:

said eccentric means has a body with a pair of sides for slidablycontacting said sides in said opening, said body has a circular openingwith a cylindrical member rotatably positioned therein, and drive shaftmeans for rotating said cylindrical member having an axis of rotationoffset from the axis of said cylindrical member. 12. An oscillatingpower unit as claimed in claim 11 in which:

said drive shaft means includes a drive shaft with an enlargedcylindrical lobe, the axis of which is offset from the axis of saiddrive shaft, said lobe is rotatable in said body, and means for fixingsaid cylindrical member to said lobe at given rotational positionstherebetween, whereby the eccentric throw of said lobe may beselectively adjusted. 13. An oscillating power unit as claimed in claim12 in which:

the axis of said cylindrical opening in said cylindrical member isoffset from the axis of said cylindrical member. 14. An oscillatingpower unit as claimed in claim 13 in which:

said oscillator has a cylindrical shape with flat end surfaces, a framefor supporting said pivot having flat ends adjacent said flat endssurfaces and a housing having a cylindrical opening for enclosing saidoscillator, and said oscillator having oil passages through to saidopening at the top and bottom thereof. 15. An oscillating power unit asclaimed in claim 13 in which:

said cylindrical member having at least two separatable, axial parts forfitting against the axial ends of said lobe, and clamp means for drawingsaid parts axially to a fixed position against said lobe. 16. Anoscillating power unit as claimed in claim 15 in which:

said cylindrical member having means for separating said separable partsupon releasing said clamp means. 17. An oscillating power unit asclaimed in claim 14 in which:

said flat ends of said frame having means for supporting said driveshaft, said cylindrical member has a radial slot in the surface adjacentone of said flat ends, and releasable pin means in said one of said flatends for selectively projecting into said slot and maintainingorientation of said cylindrical member upon rotation of said lobe.

1. An oscillating power unit comprising: a hollow casing havingenclosing end plates thereon, a drive shaft rotatably mounted in saidcasing between said end plates, a rocker pin fixed in said casingsubstantially parallel to and radially offset from said drive shaft, anoscillatory power generating weight element pivotally mounted on saidrocker pin and enclosing said drive shaft, and adjustable throweccentric drive means coupling said drive shaft to said weight element.2. The structure of claim 1 wherein: said drive means include aneccentric lobe on said drive shaft, and a drive block eccentricallymounted on said lobe within said weight element.
 3. The structure ofclaim 2 wherein: said weight element has a slide block mounted thereinfor sliding motion substantially radial to said rocker pin, said driveblock being rotatably held in said slide block.
 4. The structure ofclaim 3 wherein: said drive block has clamp means adjustably securing itto said drive shaft.
 5. The structure of claim 3 wherein: said lobe hasaxially tapered portions, said drive block being in two axiallyseparated elements seating on said tapered portions with clamp meanssecuring the separated elements together.
 6. The structure of claim 5wherein: one of said end plates has removable elements exposing saidclamp means.
 7. The structure of claim 6 including: indexing means onsaid casing, selectively engageable with said drive block in oneposition in which said clamp means are aligned with said removableelements.
 8. An oscillating power unit comprising: an oscillatorpivotally supported at one side for radial rocking movement around thepivot, said oscillator having a rotatable eccentric means positionedwithin said oscillator and enclosed thereby and spaced radially fromsaid pivot for providing an orbital movement with a rotating eccentricthrow, and said eccentric means has a linear sliding drive connectionswith said oscillator and within said oscillator for translating saidorbital movement to reciprocating, radial rocking movement of saidoscillator on said pivot.
 9. An oscillating power unit as claimed inclaim 8 in which: said eccentric means and said pivot each have an axisof rotation, which are parallel and are in the same plane. 10 Anoscillating power unit as claimed in claim 9 in which: said oscillatorhas an opening with opposite linear sides, said sides are parallel withsaid plane, and an open space between the upper and lower edges of saideccentric means and said oscillator opening allowing linear movement ofsaid eccentric means in said oscillator opening.
 11. An oscillatingpower unit as claimed in claim 10 in which: said eccentric means has abody with a pair of sides for slidably contacting said sides in saidopening, said body has a circular opening with a cylindrical memberrotatably positioned therein, and drive shaft means for rotating saidcylindrical member having an axis of rotation offset from the axis ofsaid cylindrical member.
 12. An oscillating power unit as claimed inclaim 11 in which: said drive shaft means includes a drive shaft with anenlarged cylindrical lobe, the axis of which is offset from the axis ofsaid drive shaft, said lobe is rotatable in said body, and means forfixing said cylindrical member to said lobe at given rotationalpositions therebetween, whereby the eccentric throw of said lobe may beselectively adjusted.
 13. An oscillating power unit as claimed in claim12 in which: thE axis of said cylindrical opening in said cylindricalmember is offset from the axis of said cylindrical member.
 14. Anoscillating power unit as claimed in claim 13 in which: said oscillatorhas a cylindrical shape with flat end surfaces, a frame for supportingsaid pivot having flat ends adjacent said flat ends surfaces and ahousing having a cylindrical opening for enclosing said oscillator, andsaid oscillator having oil passages through to said opening at the topand bottom thereof.
 15. An oscillating power unit as claimed in claim 13in which: said cylindrical member having at least two separatable, axialparts for fitting against the axial ends of said lobe, and clamp meansfor drawing said parts axially to a fixed position against said lobe.16. An oscillating power unit as claimed in claim 15 in which: saidcylindrical member having means for separating said separable parts uponreleasing said clamp means.
 17. An oscillating power unit as claimed inclaim 14 in which: said flat ends of said frame having means forsupporting said drive shaft, said cylindrical member has a radial slotin the surface adjacent one of said flat ends, and releasable pin meansin said one of said flat ends for selectively projecting into said slotand maintaining orientation of said cylindrical member upon rotation ofsaid lobe.